1. Field of the Invention
The present invention relates to image processing apparatuses, image processing methods, and programs, and more particularly, to an image processing apparatus, an image processing method, and a program that enable users to receive high-quality image data.
2. Description of the Related Art
In existing terrestrial analog broadcasting, standard definition (SD) images having an aspect ratio of 4:3 corresponding to composite signals in compliance with the National Television System Committee (NTSC) system are broadcast.
In recent years, in addition to existing terrestrial analog broadcasting, terrestrial digital broadcasting has started. In terrestrial digital broadcasting, SD images having an aspect ratio of 16:9, so-called “D1 images”, or high definition (HD) images are broadcast in the form of component signals, and thus, higher quality images can be provided compared to images provided by terrestrial analog broadcasting.
Broadcasting equipment, such as cameras for capturing SD images having an aspect ratio of 16:9 (hereinafter referred to as “D1 images”) or HD images, is expensive so that it takes time before such expensive broadcasting equipment will be widely used in broadcasting stations.
Accordingly, in some broadcasting stations, composite signal images to be broadcast in terrestrial analog broadcasting are converted into component signal images, and then, the component signal images are up-converted by increasing the number of pixels by interpolation. With this operation, only the format of the resulting images becomes the same as that of D1 images or HD images, which are broadcast in terrestrial digital broadcasting.
Images having the same format as that of D1 images or HD images by converting composite signal images into component signal images and by up-converting the component signal images are hereinafter referred to as “quasi-D1 images” or “quasi-HD images”.
Since quasi-D1 images or quasi-HD images are images generated by converting composite signal images into component signal images, noise, so-called “cross-color” or “dot crawl”, occurs in such quasi-images. Also, since quasi-D1 images or quasi-HD images are images generated by up-converting component signal images converted from composite signal images, noise, so-called “cross-color” or “dot crawl”, becomes even noticeable by up-conversion. In particular, in quasi-HD images, noise, so-called “cross-color” or “dot crawl”, becomes even more noticeable since the number of pixels to be interpolated by up-conversion is larger than that in quasi-D1 images.
A method for converting images into high-quality images by considering the characteristics unique to composite signals has been proposed in, for example, Japanese Unexamined Patent Application Publication No. 10-056622.